Efeito do processo de secagem no potencial antioxidante e na composição fitoquímica de plantas medicinais da família Fabaceae

As flores de várias espécies dos géneros Cytisus e Genista (da Tribo Genisteae, família Fabaceae) são muito utilizadas em todo o Mediterrâneo, e em particular na região do Nordeste de Portugal, para fins medicinais e condimentares. Tradicionalmente procede-se à secagem destas flores logo após a colheita, mantendo-as à sombra e à temperatura ambiente durante um período de cerca de 30 dias. No entanto, o processo de liofilização tem vindo a ser indicado como uma melhor alternativa para a preservação da qualidade das amostras de material vegetal. Neste trabalho, avaliaram-se os efeitos do processo de secagem (tradicional versus liofilização) no potencial antioxidante e na composição fitoquímica de flores de Cytisus multiflorus (L'Hér.) Sweet (giesta branca), Cytisus scoparius (L.) Link (giesta negral), Cytisus striatus (Hill) Rothm. (giesta amarela) e Pterospartum tridentatum (L.) Willk (carqueja). As propriedades antioxidantes foram avaliadas por métodos bioquímicos (inibição da descoloração do β-caroteno na presença de radicais livres derivados do ácido linoleico e inibição da formação de espécies reativas do ácido tiobarbitúrico (TBARS) em homogeneizados cerebrais) e métodos químicos (determinação do poder redutor e da capacidade captadora de radicais 2,2-difenil-1-picril-hidrazilo (DPPH)). Determinaram-se antioxidantes hidrofílicos (ácido ascórbico, fenóis incluindo flavonóis e ésteres tartáricos e açúcares) e lipofílicos (carotenoides incluindo β-caroteno e licopeno, clorofilas, tocoferóis e ácidos gordos). O valor energético das amostras também foi calculado com base nos níveis totais de lípidos, proteínas e glúcidos. A amostra liofilizada de Pterospartum tridentatum apresentou a maior atividade antioxidante (valores de EC50 0,15 mg/mL), o que está de acordo com os seus níveis mais elevados de fenóis (~520 mg EACl/g extrato). As amostras liofilizadas demonstraram sempre maior bioatividade e maiores concentrações de antioxidantes hidrofílicos (fenóis, ácido ascórbico e açúcares) e lipofílicos (tocoferóis, clorofilas e licopeno). No entanto, o processo de secagem não teve influência significativa na contribuição energética (que variou entre 386 e 404 kcal/100 g de massa seca). Os resultados obtidos dão suporte técnico e científico aos usos tradicionais destas plantas na medicina popular como anti-inflamatórios, destacando-as como fonte de compostos bioativos. Mais ainda, a liofilização mostrou preservar de uma forma mais eficaz as qualidades das plantas medicinais em estudo, podendo ser aplicada a plantas medicinais para utilizações na indústria cosmética ou farmacêutica.Flowers from several common Mediterranean shrubs, such as those from the Cytisus genus and Genista genus (tribe Genisteae/Fabaceae) have long been used for medicinal purposes and seasoning in the northeastern Portuguese region. Despite, the shade-drying traditionally used to process these plants, freeze-drying is claimed to better preserve the quality of medicinal plants. Herein, the effects of drying process in the antioxidants composition and properties of Cytisus multiflorus (L'Hér.) Sweet (white Spanish broom), Cytisus scoparius (L.) Link (common broom), Cytisus striatus (Hill) Rothm. (Portuguese broom) and Pterospartum tridentatum (L.) Willk were evaluated. The antioxidant activity was evaluated by biochemical (β-carotene bleaching inhibition in the presence of free radicals derived from linoleic acid and inhibition of lipid peroxidation though thiobarbituric acid reactive substances (TBARS) assay) and chemical methods (2,2-diphenyl-1-pycrilhydrazil (DPPH) radical scavenging capacity and reducing power). Hydrophilic (ascorbic acid, sugars and phenolics including flavonols and tartaric esters) and lipophilic (carotenoids including β-carotene and lycopene, chlorophylls, tocopherols, and fatty acids) compounds were quantified. The energetic value of the samples was also calculated based on the total levels of fats, proteins and carbohydrates. Pterospartum tridentatum submitted to freeze- or shade-drying proved to be the species with highest antioxidant capacity in all the assayed methods (lowest EC50 values), which is in agreement to its highest levels of phenolics (~500 mg ClAE/g extract). Freeze-drying benefits were confirmed showing, the samples submitted to this process, higher antioxidant activity and higher concentrations of hydrophilic (phenolics, ascorbic acid and sugars) and lipophilic (tocopherols, chlorophylls and lycopene) compounds. Nevertheless, the drying process did not have significantly influence in energetic contribution (values ranging from 386 and 404 kcal/100 g dry weight). The results give technical and scientific support to the traditional uses of these plants in folk medicine as anti-inflammatory, highlighting them as a source of bioactive compounds. Moreover, the drying process to be used in industrial applications is very important, since freeze-drying proved to preserve more the quality of the studied medicinal plants. This process could be applied in scale-up treatments of the studied plants for cosmetic or pharmaceutical applications

Nutritional composition and antioxidant activity of four tomato (Lycopersicon esculentum L.) farmer' varieties in Northeastern Portugal homegardens.

The nutritional and antioxidant composition of four tomato Portuguese farmer’ varieties widely cultivated in homegardens was determined. The analysed components included macronutrients, individual profiles of sugars and fatty acids by chromatographic techniques, hydrophilic antioxidants such as vitamin C, phenolics, flavonols and anthocyanins, and lipophilic antioxidants such as tocopherols, β-carotene and lycopene. Furthermore, the antioxidant activity was evaluated through DPPH scavenging activity, reducing power, beta-carotene bleaching inhibition and TBARS formation inhibition. One of the four varieties, which is locally known as round tomato or potato tomato, proved to be the most powerful in antioxidant activity (EC50 values ≤ 1.63 mg/ml), phenolic compounds (phenolics 31.23 mg ClAE/g extract, flavonols 6.36 mg QE/g extract and anthocyanins 3.45 mg ME/g extract) and carotenoids (β-carotene 0.51 mg/100 g and lycopene 9.49 mg/100 g), while the so-called yellow tomato variety revealed interesting nutritional composition, including higher fructose (3.42 g/100 g), glucose (3.18 g/100 g), alpha-linolenic acid (15.53%) and total tocopherols (1.44 mg/100 g) levels. Overall, these farmer’ varieties of garden tomato cultivated in the northeastern Portuguese region could contribute as sources of important antioxidants related to the prevention of chronic diseases associated to oxidative stress, such as cancer and coronary artery disease

Recovery of bioactive polyphenols from Aloe vera (Aloe barbadensis Mill.) rind using binary mixtures of propylene glycol and water

Aloe vera (Aloe barbadensis Mill.) is a succulent plant species cultivated worldwide for its jelly-like parenchyma that is used by cosmetic, pharmaceutical and nutraceutical industries. This gel fillet is found protected by a thick layer (green rind) that constitutes 20-30% of the whole leaf weight [1], which is often discarded as waste. However, this biowaste can be valorised as a source of high added-value compounds [2]. Today, the principles of green chemistry have been introduced into extraction schemes with the aim of making processes more sustainable. Some studies have also shown that polyols in aqueous solution may constitute a very suitable extraction medium for polyphenol recovery [3]. Therefore, this study was carried out to characterize the phenolic profile of Aloe vera rind, evaluate antioxidant properties, and investigate the suitability of propylene glycol-water mixtures for extracting these bioactives. The leaf rind was separated from the fillet gel parenchyma, freeze-dried and reduced to a fine powder. First, a solid-liquid extraction was performed with ethanol/water (80:20, v/v) to obtain a combined extract, from which the phenolic profile was characterized by HPLC-DAD-ESI/MS and the antioxidant activity was evaluated by the in vitro cell-based assays of TBARS (thiobarbituric acid reactive substances) and OxHLIA (oxidative haemolysis inhibition assay) [4]. Afterwards, binary mixtures of propylene glycol (propane-1,2-diol)-water (from 0 to 95 %, w/w) were used in extractions performed at 50 oC for 60 min, whose efficiency was monitored based on the total phenolic and flavonoid contents, measured by colorimetric methods [5]. Different phenolic compounds were identified in the Aloe vera rind extract, including chromones (aloesin A and B), anthrones (aloin A and B), and flavones (luteolin and apigenin glucoside derivatives). Aloesin and aloin (Figures 1 and 2) are recognized for their skin regeneration (wound healing) and laxative effects, respectively, being among the most important physiologically active compounds found in Aloe [6,7]. The combined extract also had interesting antioxidant properties, being particularly effective in protecting erythrocytes from the free radical-induced oxidative damage, with an IC50 value close to that of the positive control, trolox. Regarding the effect of the extraction solvents on the recovery of total phenolics and flavonoids, it was found that intermediate propylene glycol-water mixtures lead to higher amounts than when used alone. Thus, this study showed that Aloe vera rind can be used as an interesting source of bioactive compounds and that propylene glycol in aqueous solution may improve its extraction.Acknowledgements: To the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013) and the research contracts of J. Pinela (Project AllNatt, POCI-01-0145-FEDER-030463) and L. Barros. To POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by ERDF, through POCI-COMPETE2020 and FCT. This work was funded by the European Regional Development Fund (ERDF) through the Competitiveness and Internationalization Operational Program (POCI) and national funding through FCT, within the scope of Project POCI-01-0145-FEDER-030463: AllNat. To FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E. Also to the company "Courela do Alentejo" for the plant samples.info:eu-repo/semantics/publishedVersio

Composição fitoquímica e bioactividade de flores de espécies medicinais tradicionalmente usadas no Nordeste de Portugal.

As autoridades de Saúde Pública consideram o uso de produtos naturais na prevenção e tratamento de doenças um instrumento fundamental para a manutenção e promoção da saúde, longevidade e qualidade de vida. Efectivamente, os usos tradicionais de plantas aromáticas e medicinais têm grande impacto no desenvolvimento de novos produtos à base de plantas. Cytisus multiflorus (L'Hér.) Sweet (giesta-branca), Crataegus monogyna Jacq. (espinheiro), Filipendula ulmaria (L.) Maxim. (rainha-dos-prados), Malva sylvestris L. (malva) e Sambucus nigra L. (sabugueiro) são espécies que têm sido utilizadas na Península Ibérica como plantas medicinais. Para além de outras aplicações, estas espécies tornaram-se ingredientes importantes na preparação de remédios caseiros devido às suas propriedades anti-inflamatórias, diuréticas e diaforéticas. Neste trabalho, apresentaremos um estudo comparativo da composição fitoquímica e do potencial antioxidante de flores das espécies mencionadas, com vista à caracterização etnofarmacológica e valorização da flora portuguesa. A análise fitoquímica incluiu a determinação de compostos fenólicos por HPLC-UV/DAD-MS, tocoferóis por HPLC/fluorescência, mono e oligossacáridos por HPLC/RI e ácidos gordos por GC/FID. O potencial antioxidante foi avaliado por métodos químicos e ensaios bioquímicos com homogeneizados de células animais (eritrócitos e células cerebrais)

Caracterização nutricional e propriedades bioativas de quatro variedades tradicionais de tomate (Lycopersicon esculentum L.) cultivadas no Nordeste de Portugal.

Determinou-se a composição nutricional e a atividade antioxidante de quatro variedades tradicionais de tomate da região de Trás-os-Montes, conhecidas como amarelo, batateiro, comprido e coração. Analisaram-se cromatograficamente ácidos gordos, açúcares e tocoferóis, bem como vitamina C, β-caroteno, licopeno, fenóis, flavonóis e antocianinas. A atividade antioxidante foi avaliada através dos ensaios da capacidade captadora de radicais DPPH, do poder redutor e da inibição da peroxidação lipídica no sistema β-caroteno linoleato e na presença de TBARS em homogeneizados cerebrais. A variedade de tomate batateiro demonstrou a maior atividade antioxidante (valores EC50 ≤ 1,63 mg/mL) e o maior teor em compostos fenólicos (fenóis totais 31,23 mg/g extrato, flavonóis 6,36 mg/g extrato e antocianinas 3,45 mg/g extrato) e carotenoides (β-caroteno 0,51 mg/100 g e licopeno 9,49 mg/100 g), enquanto que a variedade de tomate amarelo revelou uma interessante composição nutricional, apresentando níveis elevados de frutose (3,42 g/100 g), glucose (3,18 g/100 g), ácido α-linolénico (15,53%) e tocoferóis totais (1,44 mg/100 g). No geral, as variedades tradicionais de tomate estudadas, cultivadas no Nordeste de Portugal, poderão contribuir como importante fonte de antioxidantes relacionados com a prevenção de doenças crónicas associadas ao stresse oxidativo, como o cancro e doença arterial coronária. Por outro lado, os resultados validam e confirmam a importância dos usos locais destas variedades

Influence of the drying method in the antioxidant potential and chemical composition of four shrubby flowering plants from the tribe Genisteae (Fabaceae).

Flowers from several common Mediterranean shrubs, such as those from the Cytisus genus and Genista genus (tribe Genisteae/Fabaceae) have long been used for medicinal purposes and seasoning in the northeastern Portuguese region. Despite, the shade-drying traditionally used to process these plants, freeze-drying is claimed to better preserve the quality of medicinal plants. Herein, the effects of drying process in the antioxidants composition and properties of Cytisus multiflorus, Cytisus scoparius, Cytisus striatus and Pterospartum tridentatum were evaluated. Freeze-dried P. tridentatum revealed the highest antioxidant properties (EC50 values <= 0.15 mg/ml). Freeze-drying benefits were confirmed showing, the samples submitted to this process, higher antioxidant activity and higher concentrations of hydrophilic (phenolics, ascorbic acid and sugars) and lipophilic (tocopherols, chlorophylls and lycopene) compounds. This process could be applied in scale-up treatments of the studied plants for cosmetic or pharmaceutical applications

Characterization and quantification of phenolic compounds in four tomato (Lycopersicon esculentum L.) farmer’ varieties in Northeastern Portugal homegardens.

Tomato (Lycopersicon esculentum L.) is one of the most widely consumed fresh and processed vegetables in the world, and contains bioactive key components. Phenolic compounds are one of those components and, according to the present study, farmers’ varieties of tomato cultivated in homegardens from the northeastern Portuguese region are a source of phenolic compounds, mainly phenolic acid derivatives. Using HPLC-DAD-ESI/MS, it was concluded that a cis p-coumaric acid derivative was the most abundant compound in yellow (Amarelo) and round (Batateiro) tomato varieties, while 4-O-caffeolyquinic acid was the most abundant in long (Comprido) and heart (Coração) varieties. The most abundant flavonoid was quercetin pentosylrutinoside in the four tomato varieties. Yellow tomato presented the highest levels of phenolic compounds (54.23 μg/g fw), including phenolic acids (43.30 μg/g fw) and flavonoids (10.93 μg/g fw). The phenolic compounds profile obtained for the studied varieties is different from other tomato varieties available in different countries, which is certainly related to genetic features, cultivation conditions, and handling and storage methods associated to each sample

Argon vs Nitrogen: what is the most effective gas for shelf-life extension of buckler sorrel?

Buckler sorrel (Rumex induratus Boiss. & Reut.; Polygonaceae) is an underutilized leafy vegetable with peculiar sensory properties and potential as a gourmet food product. In the food industry, different packaging methods have been used for shelf-life extension, but it is important to know how the quality of minimally processed vegetable is affected by these treatments. Recently, nitrogen and argon have been used for food packaging. Nitrogen is low soluble in water and other food constituents and does not support the growth of aerobic microbes. In turn, argon is biochemically active and appears to interfere with enzymatic oxygen receptor sites. Herein, modified atmospheres enriched with nitrogen and argon were evaluated for shelf-life extension of buckler sorrel leaves.info:eu-repo/semantics/publishedVersio